Those looking to expand on the Halo 3 experience can enjoy some brand new content. Available now on the Xbox Live Marketplace are a few limited-time Halo-related items. The following items are only available to Xbox Live Gold members, and will only be available until September 30.

Halo 3 Dashboard Theme

Halo 3 Gamerpic

"Inside Bungie: Halo 3 – The Story" video: Interviews with the Bungie team

"Inside Bungie: Halo 3 – New Features" video: Interviews with the Bungie team about the new Halo 3 game features

I can imagine the free theme and gamerpic being quite popular, especially since many gamers are enjoying a few free days of Xbox Live Gold, which should allow you to snag these if you're quick. Don't miss the other trailers and ads for the game that are already available on the Marketplace, too.